Along with the coming of the information age, the demand for display devices as information presenting media continuously increases. Cathode ray tube (CRT) displays, having good display performance and being technologically mature, have dominated the display market for decades. However, recently developed high-tech products, such as LCDs, tend to be slimmer and better miniaturized. Therefore, LCDs with the advantages such as higher display quality, less space demand, lower power consumption and non-radiation technology gradually replace conventional CRT displays and become a mainstream in the display market.
Both of the foregoing two type displays have their advantages and disadvantages. A CRT display uses an electron beam in an impulse type driving to emit light. In other words, in a frame time (about 16.7 ms at 60 Hz refresh rate), the amplitude of a pixel brightness of the CRT display varies with time, so that the CRT display is adapted for displaying dynamic frames. However, when displaying static frames, such a CRT display is likely to cause flickering problems. Watching such flickering static frames for a long time may leave viewers' eyes uncomfortable.
As to LCD displays, most of them are driven to emit light in a hold type. In other words, in each frame time, the amplitude of backlight provided by a backlight source is constant. Therefore, LCD displays do not flicker when displaying static frames, which are more comfortable to viewers' eyes. However, such a backlight source when displaying dynamic frames causes problems of frame blurring due to the visual characteristics of human eyes.
In order to obtain better display performance, some LCD displays use impulse type backlight sources for displaying dynamic frames. Although such LCDs perform as good as CRT displays when displaying dynamic frames, unfortunately, they also suffer from CRT-like poor performance when displaying static frames.